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Zhang D.,China Railway Baoji Bridge Group Co. | Gao F.,China Railway Baoji Bridge Group Co. | Zhang J.,China Railway Baoji Bridge Group Co.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2012

Induction heating experiment with spray fog cooling was carried out on 60AT-PG4 switch rail for turnouts of heavy-haul railway. The chemical composition and the microstructure and hardness on different cross-section of switch rail were measured. The results show that the hardened layer depth of rail head of PG4 switch rail on different cross-section is 12-40 mm and the hardness on cross-section is 39-41.5 HRC. The hardened layer depth of two sides of rail head is 9-11 mm and the hardness on cross-section is 37.5-42 HRC, the microstructure in hardened layer is sorbite. The average tread surface hardness of switch rail head is 388 HB. These can meet technical requirements for the standards of TB/T 1779-1993 "Technical rule for quenching of rail turnouts" and GFKB014-2009 "Technical rule for heat treatment of rails".


Zhang D.,China Railway Baoji Bridge Group Co. | Gao F.,China Railway Baoji Bridge Group Co. | Lu W.,China Railway Baoji Bridge Group Co. | Ji N.,China Railway Baoji Bridge Group Co.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2016

Preheating treatment and induction hardening and jetting air and spray cooling process were carried out on forming heel-end 60AT1-U75V steel rail. The microstructure and depth of hardened layer, hardness of surface and cross-section, tensile strength and elongation of the rail were investigated. The results show that after induction heat treatment, the harden layer depth of the forming heel-end of 60AT1-U75V steel rail is in the range of 16.5-20.5 mm, the microstructure of the hardened layer is sorbite, the cross-section hardness of the hardened layer from the surface to the depth of 12 mm is 36.0-41.0 HRC, the surface hardness is 375-396 HB, the tensile strength Rm is more than 1242 MPa and the elongation is more than 10.8 %, which meets the requirements of TB/T 2635-2004 Technical specifications for the heat treated rails. © 2016, Chinese Mechanical Engineering Society of Heat Treatment. All right reserved.


Gao F.,China Railway Baoji Bridge Group Co. | Lu W.,China Railway Baoji Bridge Group Co. | Zhang D.,China Railway Baoji Bridge Group Co.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2013

Process of induction heat treatment of channel guard rails for heavy-haul railway turnout was carried out by two novel designed styles inductor. Distortion, chemical composition, microstructure, hardness and the hardened depth were measured. The results show that the depth hardened depth is more than 25 mm, the surface hardness is 345-370 HB, the hardness of cross-section is 34-39 HRC, and the microstructure of guard rails is sorbite, which meet the technical requirements of TB/T 3110-2008«33 kg/m Channel for Guard Rails». The structure of the first designed inductor is rational. The distortion of the channel guard rails is small. The structure of the first designed inductor is operable which can meet the demands of batch production.


Fei W.-Z.,China Railway Baoji Bridge Group Co.
Journal of Railway Engineering Society | Year: 2013

Research purposes: The research was done on the significance of turnout stiffness homogenization and the setting method for the stiffness homogenization for high-speed turnouts at home and abroad to contrast the stiffness homogenization methods and results in different countries for evaluating the stiffness homogenization result in China. Research conclusions: (1) The stiffness homogenization in turnout area is particularly important to the regularity, safety, comfortableness and service life of high-speed turnouts. (2) For the France's turnouts, the stiffness homogenization is achieved by increasing the rubber pad stiffness, and this method is simple without using the transition section. (3) For the Germany's turnouts, the elasticity of the pad is controlled strictly by vulcanization, and both the design and manufacture are complicated. (4) For the China's high-speed turnouts, the turnout is divided into different sections according to different structure, and the stiffness homogenization is achieved by vulcanization. (5) Although the measures taken by the countries are different, but the stiffness homogenization in turnout area are achieved in different countries. (6) The turnout dynamic test and application show the method and measures used for the stiffness homogenization of the high-speed turnout in China are reasonable and feasible.


Wang L.-J.,Chang'an University | Yang J.-S.,China Railway Baoji Bridge Group Co. | Sun B.,Chang'an University | Tian X.-D.,Chang'an University
Advanced Materials Research | Year: 2011

A composite coating was prepared on Ti-6Al-4V surface by the combination of nitriding, Mo-sputtering and sulfurizing treatments. The microstructure and phase constituent of the composite coating were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Furthermore, the cross-sectional hardness gradient of the coating was determined. The results revealed that the composite coating consisted of Ti, Mo, MoS2, TiN and transition layer and the grain size of the sulfides formed on the coating surface were different with treatment temperature. The examination of the cross-sectional hardness of the composite coating revealed that the coating was an ideal tribological surface.


Piao L.,Hong Kong Zhuhai Macau Bridge Authority | Zhou G.-M.,China Railway Baoji Bridge Group Co. | Wu X.-B.,China Railway Baoji Bridge Group Co. | Hu Y.,China Railway Major Bridge Engineering Group Co. | Li J.-P.,China Railway Baoji Bridge Group Co.
Bridge Construction | Year: 2016

The non-navigable bridge of the Hong Kong-Zhuhai-Macau Bridge over the shallow water area is a 85-m span steel and concrete continuous composite girder bridge. The composite girder of the bridge is comprised of the concrete deck slabs and steel main girder that were connected by the clustered shear studs. The deck slabs were cast in one time in the precasting yard and the main girder was manufactured and assembled in each full span in 3 stages of the plate unit manufacturing, segment manufacturing and general assembling. After the general assembling of the main girder was completed, the deck slabs and the girder were bonded, using the epoxy mortar and were transported to and erected at the bridge site in each full span by the 3 000 t Tianyi Vessel. In the whole construction of the composite girder of the bridge, the following new techniques were used, i.e. the longitudinal butt joints of the bottom plate units of the main girder were welded, using the preset counter-camber jigs and the workmanship of one-side welding and two-side shaping. For the integral manufacturing of the diaphragm and bottom plate units, the welding was carried out, using the automatic welding robots. At the time of the general assembling of the main girder, the butt joints of the webs of the girder were vertically welded, using the rail-mounted digital welding robots and the penetration joints of the webs and bottom plates were welded, using the blind-area-free welding trolleys. © 2016, Journal Press, China Railway Bridge Science. All right reserved.


Gao F.,China Railway Baoji Bridge Group Co. | Zhang D.-W.,China Railway Baoji Bridge Group Co. | Zhang J.-G.,China Railway Baoji Bridge Group Co.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2011

The switch and stock rail of high speed rail turnout with the length more than 20 m were tested by induction hardening. Deformation and mechanical properties of the switch and stock rail after heat treatment were measured. The results show that the hardened layer depth for head of rail is more than 10 mm, the hardness in cross-section is 34-38 HRC, and the optical microstructure is fine pearlite and a few ferrite. By pre-deformation for the length 20-24 m rail, the deflection of the rail can be controlled in the range of 150 mm, so that, which can meet technical requirements of high speed turnout assembly.

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